There is a strong demand and need for a vortex shedding flowmeter technology that teaches the construction of a vortex flowmeter of small port size with a short over-all length, e.g., preferably one and half to one inch in the flow passage diameter with comparable over-all length, which has good sensitivity and excellent immunity to the mechanical vibrations of the flowmeter body and the pipe line accommodating the vortex flowmeter, as such a vortex flowmeter can be packaged into an insertion type flowmeter mounted on one extremity of an elongated support member, that is inserted into and disposed in the midstream of fluid flow moving through a large diameter conduit. Of course, such a vortex shedding flowmeter technology also provides an advantage in constructing inline vortex flowmeters of wide ranging sizes, which have excellent performance characteristics and economics in price and maintenance.